The irritable bowel syndrome syndrome (IBS) is a common disorder of intestinal motility that is defined by clinical criteria: altered bowel function (episodes of constipation and diarrhea) and often abdominal pain. Evidence based on retrospective case analyses, psychatric interviews and psychologic testing support therole of stress in influencing bowel symptions and suggest that patients with this disorder have a higher prevalence of psychiatric diagnoses than other medical or healthy comparison groups. However, we do not know how representative the patient population is for all with the IBS. We have confirmed an earlier study that bowel dysfunction symtomatically compatible with the irritable bowel syndrome exists in a substantial portion of the general population. Evaluation of the role of stress and other psychosocial factors in this larger population has not been done. The purpose of our study is twofold. First, we plant to survey a healthy population sample to determine the range of bowel patterns. Secondly, we plan to make a psychologic comparison among medical outpatients recently diagnosed to have the irritable bowel syndrome, subjects who have thesame symptoms but who do not seek treatment, nd subjects without bowel symptoms. This is to determine whether the psychosocial data reported represent all individuals with the IBS or the subgroup of patients who end up in the health care system. Inclusion in the study will be based on sufficient positive responses to a validated questionnaire that identifies subjects with bowel dysfunction. Diagnostic evaluation will be done to exclude other medical disorders. Subjects will also keep daily records of their bowel patterns to match the two groups with regard to sympton severity. Semistructured psychiatric interviews and standardized psychologic tests will be used to determine the prevalence of the personality patterns commonly reported in this syndrome. Quantitation of antecedent life events and the role of social support systems will also be obtained. With this information, we expect that more accurate prevalence data of the psychologic patterns of subjects with irritable bowel will be provided. We also expect to obtain information about the role of stress and patient personality and behavior as determinants of health care seeking behavior.